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SpatialFilterCommand Class
See Also  Members   Example 
Leadtools.ImageProcessing.Effects Namespace : SpatialFilterCommand Class



Imposes a spatial filter on an image. This command is available in the Document/Medical Toolkits.

Syntax

Visual Basic (Declaration) 
Public Class SpatialFilterCommand 
   Inherits RasterCommand
   Implements IRasterCommand 
Visual Basic (Usage)Copy Code
Dim instance As SpatialFilterCommand
C# 
public class SpatialFilterCommand : RasterCommand, IRasterCommand 
C++/CLI 
public ref class SpatialFilterCommand : public RasterCommand, IRasterCommand 

Example

Run the SpatialFilterCommand on an image and applies a Prewitt edge detection filter.

Visual BasicCopy Code
Public Sub SpatialFilterCommandExample()
   RasterCodecs.Startup()
   Dim codecs As New RasterCodecs()
   codecs.ThrowExceptionsOnInvalidImages = True

   Dim leadImage As RasterImage = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "Master.jpg")

   ' Prepare the command
   Dim command As SpatialFilterCommand = New SpatialFilterCommand(SpatialFilterCommandPredefined.PrewittHorizontal)
   'Apply a Prewitt edge detection filter.

   command.Run(leadImage)
   codecs.Save(leadImage, LeadtoolsExamples.Common.ImagesPath.Path + "Result.jpg", RasterImageFormat.Jpeg, 24)

   RasterCodecs.Shutdown()
End Sub
C#Copy Code
public void SpatialFilterCommandExample() 
{ 
   // Load an image 
   RasterCodecs.Startup(); 
   RasterCodecs codecs = new RasterCodecs(); 
   codecs.ThrowExceptionsOnInvalidImages = true; 
 
   RasterImage image = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "Master.jpg"); 
 
   // Prepare the command 
   SpatialFilterCommand command = new SpatialFilterCommand(SpatialFilterCommandPredefined.PrewittHorizontal); 
   //Apply a Prewitt edge detection filter. 
   command.Run(image); 
 
   RasterCodecs.Shutdown(); 
}

Remarks

  • A spatial filter recomputes the brightness of each pixel in an image by using a weighted averaging technique that considers the surrounding pixels. Spatial filters are used for operations such as sharpening an image or detecting edges within the image.
  • The SpatialFilterCommand works best with 24-bit, 16-bit, or grayscale images. If the image uses a color palette, this command matches the new brightness value of each pixel to the nearest color in the existing palette.
  • This command supports 12 and 16-bit grayscale and 48 and 64-bit color images. Support for 12 and 16-bit grayscale and 48 and 64-bit color images is available only in the Document/Medical toolkits.
  • It is beyond the scope of this documentation to explain how applying various weighting factors affects an image. If you specify your own filter, you should refer to a textbook on image processing. For example, Digital Image Processing: Principles and Applications, by Gregory A. Baxes.
  • This command does not support 32-bit grayscale images.
For more information, refer to Detecting and Enhancing Edges and Lines.
For more information, refer to List of Spatial Filters.

Inheritance Hierarchy

System.Object
   Leadtools.ImageProcessing.RasterCommand
      Leadtools.ImageProcessing.Effects.SpatialFilterCommand

Requirements

Target Platforms: Microsoft .NET Framework 2.0, Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

See Also